Method and apparatus to facilitate broadcast packet handling

ABSTRACT

A first network element determines ( 11 ) that a given mobile node using mobile Internet Protocol should receive subsequent broadcast packets as may be sourced by a corresponding Home Agent. This first network element can then determine ( 12 ) whether to support such subsequent broadcast packets using a first broadcast packet handling approach or a second broadcast packet handling approach.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of and claims the benefitunder 35 U.S.C. §120 to U.S. patent application Ser. No. 11/034,614,entitled “METHOD AND APPARATUS TO FACILITATE BROADCAST PACKET HANDLING,”filed Jan. 13, 2005, assigned to the same assignee as the presentapplication, and which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

This invention relates generally to Internet Protocol-based broadcastpackets.

BACKGROUND

The Internet and its enabling protocols are well known. This includessupport for so-called broadcast packets (such as, but not limited to,emergency notifications, system control packets, and so forth). Inparticular, the present Internet Protocol provides a mechanism whereby,for example, a Home Agent can send a given packet to a number ofdifferent recipients (hence the moniker “broadcast”).

At present, a Mobile Internet Protocol node that wishes to receivebroadcast packets from its Home Agent will send a Mobile InternetProtocol registration request message with its “B” bit set. The servingPacket Data Serving Node for this Mobile Internet Protocol node willthen forward this request to the Home Agent and service the Home Agent'sresponse as well. Later, when a broadcast packet arrives at the HomeAgent for further distribution, the latter will encapsulate thebroadcast packet in a unicast datagram and tunnel this encapsulateddatagram to the Packet Data Serving Node. The Packet Data Serving Nodewill then decapsulate this message and forward it to the Mobile InternetProtocol node.

If, however, multiple Mobile Internet Protocol nodes as are served bythis Packet Data Serving Node/Home Agent pair request the forwarding ofbroadcast packets, the same broadcast packet will be sent over severaldifferent Mobile Internet Protocol tunnels from the Home Agent to thePacket Data Serving Node. In turn, each of these identical butindividual broadcast packets is then forwarded on by the Packet DataServing Node to the respective Mobile Internet Protocol nodes.

Such an approach, while successful in the sense of accomplishing thedesired end result of facilitating the distribution of broadcastpackets, nevertheless leaves much to be desired. In particular, thisapproach tends to result in a considerable volume of traffic between theHome Agent and Packet Data Serving Node.

BRIEF DESCRIPTION OF THE DRAWINGS

The above needs are at least partially met through provision of themethod and apparatus to facilitate broadcast packet handling describedin the following detailed description, particularly when studied inconjunction with the drawings, wherein:

FIG. 1 comprises a flow diagram as configured in accordance with variousembodiments of the invention;

FIG. 2 comprises a flow diagram as configured in accordance with variousembodiments of the invention;

FIG. 3 comprises a block diagram as configured in accordance withvarious embodiments of the invention;

FIG. 4 comprises a flow diagram as configured in accordance with variousembodiments of the invention;

FIG. 5 comprises a block diagram as configured in accordance withvarious embodiments of the invention; and

FIG. 6 comprises a signal flow diagram as configured in accordance withvarious embodiments of the invention.

Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions and/or relative positioningof some of the elements in the figures may be exaggerated relative toother elements to help to improve understanding of various embodimentsof the present invention. Also, common but well-understood elements thatare useful or necessary in a commercially feasible embodiment are oftennot depicted in order to facilitate a less obstructed view of thesevarious embodiments of the present invention. It will also be understoodthat the terms and expressions used herein have the ordinary meaning asis accorded to such terms and expressions with respect to theircorresponding respective areas of inquiry and study except wherespecific meanings have otherwise been set forth herein.

DETAILED DESCRIPTION

Generally speaking, pursuant to these various embodiments, a firstnetwork element makes a determination regarding whether a given mobilenode using mobile Internet Protocol should receive subsequent broadcastpackets as are sourced by a corresponding Home Agent, and then makes anautomatic determination regarding whether to support such subsequentbroadcast packets using a first broadcast handling approach or a secondbroadcast packet handling approach.

In a preferred approach the first network element comprises a PacketData Serving Node.

Also pursuant to a preferred embodiment, the first broadcast handlingapproach comprises having the Home Agent transmit a discrete version ofeach subsequent broadcast packet to each mobile station as is supportedby the first network element, and the second broadcast packet handlingapproach comprises having the Home Agent transmit a shared version ofeach subsequent broadcast packet to each mobile station as is supportedby the first network element.

So configured, these teachings when employed typically effectconsiderably improved bandwidth utilization of the Home Agent to PacketData Serving Node link when supporting broadcast packets. In particular,these teachings tend to minimize (or at least reduce) the data trafficthat is sent from the Home Agent to the Packet Data Serving Node whenseveral mobile nodes as are served by this Home Agent/Packet DataServing Node pair have all requested the forwarding of broadcastpackets. This, in turn, aids in reducing data network congestion.

These and other benefits may become clearer upon making a thoroughreview and study of the following detailed description. Referring now tothe drawings, and in particular to FIG. 1, a general process 10 inaccord with these teachings will first provide for a determination 11(at a first network element such as, but not limited to, a Packet DataServing Node) that a given mobile node using mobile Internet Protocolshould receive subsequent broadcast packets as are sourced by acorresponding Home Agent. This determination can comprise, for example,receiving a message at the first network element as sourced by the givenmobile node and then determining that this message comprises anindication that broadcast packets should be transmitted to the givenmobile node. As but one illustrative example, this can comprise amessage having a set mobile Internet Protocol “B” bit in accordance withwell-understood prior art practice.

This process 10 then provides for automatically determining 12 whetherto support such subsequent broadcast packets using a first broadcastpacket handling approach or a second broadcast packet handling approach.In a preferred scheme the first broadcast packet handling approachcomprises having the Home Agent transmit a discrete version of eachsubsequent broadcast packet to each mobile station as is supported bythe first network element. This scheme can be realized, for example, byuse of present broadcast packet handling in this regard. The secondbroadcast packet handling approach can then preferably comprise havingthe Home Agent transmit a shared version of each subsequent broadcastpacket to each mobile station as is supported by the first networkelement. This second approach, of course, avoids discrete transmissionsof each of a plurality of packets that are essentially (or exactly)identical to one another, as now a multitude of intended recipientseffectively share a single conveyance of the content to the networkelement from the Home Agent.

This determination can be effected in a variety of ways. Pursuant to oneapproach, the first network element conducts negotiations with the HomeAgent regarding the handling of broadcast packets. For example, thefirst network element can indicate to the Home Agent that the firstnetwork element is able to support the second broadcast packet handlingapproach (when, of course, the network element is in fact able tosupport such handling). If the Home Agent is also able to support thesecond broadcast packet handling approach, then the Home Agent and thefirst network element can thereafter use the second broadcast packethandling approach when sending subsequent broadcast packets to the givenmobile node.

When the Home Agent is not able to support the second broadcast packethandling approach, the Home Agent can instead indicate this circumstanceto the first network element (for example, by indicating that the HomeAgent will support using the first broadcast packet handling approach)and thereafter the Home Agent and the network element can use the firstbroadcast packet handling approach.

Referring now to FIG. 2, a network node (such as, but not limited to, aPacket Data Serving Node) can support the above-described process 10 by,when receiving 20 a message as was sourced by a given mobile node, thendetermining 21 whether that message comprises an indication thatbroadcast packets should be transmitted to the given mobile node (forexample, by ascertaining that the message comprises, at least in part, aset mobile Internet Protocol “B” bit). When not true, the network nodecan continue in accordance with its ordinary and usual programmedprocessing as will be well understood by those skilled in the art. Whentrue, however, the network node can then indicate 22 to the Home Agentthat it (i.e., the first network element) is able to support the secondbroadcast packet handling approach.

This indication comprises but one way that such a network node caninitiate a negotiation with the Home Agent regarding whether the firstor second broadcast packet handling approach should be subsequentlyemployed. By the present approach, the network node then determines 23whether the Home Agent will support subsequent use of the secondbroadcast packet handling approach.

When false (meaning that the Home Agent is unable or unwilling tosupport the second approach), the network node can use the firstbroadcast packet handling approach when sending subsequent broadcastpackets to the given mobile node. (This selection can occur in variousways, including because the first approach comprises a default approachand/or because the Home Agent has previously specified use of the firstapproach.) As an optional though useful step, the network node can thenalso determine 25 whether the Home Agent is presently in a listmaintained (and/or accessed) by the network node, which list identifiesHome Agents that are able to support the second broadcast packethandling approach. When false, the process can essentially conclude.When true, however, the network node can remove 26 the Home Agent fromthat list.

When the Home Agent is in fact able to support the second broadcastpacket handling approach, the network node can instead thereafter use 27the second broadcast packet handling approach when sending subsequentbroadcast packets to the given mobile node. Again, as an optional thoughuseful step, the network node can also determine 28 whether the HomeAgent is identified in its list of Home Agents that support the secondapproach. When not true, the network node can cause the inclusion 29 ofthe Home Agent in that list. In addition, if desired, the network nodecan also associate the given mobile node with that Home Agent in thelist.

Referring now to FIG. 3, such a network element 30 can be generallycomprised of a controller 31 that operably couples to a mobile nodeinterface 32, a Home Agent interface 33, and a list 34. The mobile nodeinterface 32 preferably effects an interface to a mobile InternetProtocol-compatible wireless mobile node. Such interfaces as areindicated above are well known and understood in the art. Therefore, forthe sake of brevity and the preservation of narrative focus, furtherelaboration need not and will not be presented here.

The list 34 preferably indicates whether the network element 30 is touse a first broadcast packet handling approach or a second broadcastpacket handing approach when forwarding broadcast packets from a givenHome Agent (via the Home Agent interface 33) to a given mobile node (ornodes) (via the mobile node interface 32). This list 34 can be stored,for example, in one or more corresponding memories. Such memory can belocal or remote and can be shared or dedicated as will be wellappreciated by those skilled in the art. In a preferred embodiment, thislist comprises more particularly a list of Home Agents that support thesecond broadcast packet handling approach and, optionally but againpreferably, a list of mobile nodes as are associated with each of theHome Agents in this list.

The controller 31 is preferably configured and arranged to source, whenappropriate, signaling to the Home Agent (via the Home Agent interface33) that the network element 30 supports the above-mentioned secondbroadcast packet handling approach. This controller 31 is alsopreferably configured and arranged to receive (and process accordingly)a signal from the Home Agent (via the Home Agent interface 33)indicating that the Home Agent supports (or does not support) the secondbroadcast packet handling approach. So configured, the network elementis well poised to support and facilitate the earlier-describedprocesses.

Network elements such as Packet Data Serving Nodes are well known in theart and typically comprise partially or largely programmable platforms.Those skilled in the art will therefore appreciate that such a platformcan be readily programmed to serve as the above-described controller 31,either as a dedicated capability or, more likely, as a shared enablingresource for other supported capabilities as well.

Referring now to FIG. 4, a Home Agent can support these teachings viaits own facilitating process. More particularly, upon receiving 41 anindication from a first network element that a given mobile node usingmobile Internet Protocol should receive subsequent broadcast packets asmay be sourced by the Home Agent, the Home Agent then automaticallydetermines 42 whether to support such subsequent broadcast packets usinga first broadcast packet handling approach or a second broadcast packethandling approach. The noted received indication can comprise, forexample, reception of a registration request that indicates thatsubsequent broadcast packets are to be sent to the specified mobilenode.

The above-noted determination 42 can comprise, for example, determiningwhether such a registration request comprises an indication that thefirst network element itself supports the second broadcast packethandling approach. This indication can be any suitable indication as maybest comport with the capabilities and/or limitations of a givensetting. As but one illustrative example, this indication can compriseat least one normal vendor specific extension (NVSE) that itself isunderstood to comprise an indication that the sourcing network elementsupports the second broadcast packet handling approach. The use of suchextensions for unique specific purposes is generally well understood inthe art.

When the Home Agent determines 42 to use the first broadcast packethandling approach, the Home Agent may then essentially utilize anexisting process to effect the sourcing of one-on-one packets toindividual mobile nodes when supporting a general broadcast. Again, suchprocesses are known in the art and require no further description here.

When the Home Agent determines 42 to use the second broadcast packethandling approach, the Home Agent will then preferably provide 43 anindication to the first network element that the Home Agent is, in fact,also able to support the second broadcast packet handling approach. Thisindication can take a variety of forms with a specific form beingselected in a given instance to best accommodate the needs and/orlimitations as characterize that given instance.

Optionally but preferably, the Home Agent will also include 44 the firstnetwork element in a corresponding list and will further associate 45the given mobile node with that first network element via that list aswell. So configured, the Home Agent will have an increased depth ofinformation regarding when and how to effect subsequent usage of thesecond broadcast packet handling approach, which information can beleveraged to useful effect in various ways as desired.

Referring now to FIG. 5, a Home Agent 50 will preferably comprise acontroller 51 that operably couples to a network element interface 52and a list 53 such as that noted above. More particularly, this list 53can comprise indications regarding whether to use a first or secondbroadcast packet handling approach when forwarding broadcast packets toa mobile node (or nodes) via a given network element (and hence maycomprise a list of network elements that support the second broadcastpacket handling approach and, preferably, those mobile nodes as areassociated with each of the listed network elements). As with thenetwork element described above, this list 53 can be stored or otherwiseretained using any desired storage strategy including local or remotefacilities, dedicated or shared facilities, and/or central ordistributed facilities. Such architectural options are well understoodby those skilled in the art.

In a preferred embodiment, the controller 51 is configured and arrangedto support receiving a signal from a network element indicating that thenetwork element supports the second broadcast packet handling approachand transmitting a signal to the network element indicating that theHome Agent itself supports the second broadcast packet handlingapproach. So configured, the Home Agent can readily support the variousteachings set forth above.

Home Agents are well known in the art and typically comprise partiallyor largely programmable platforms. Those skilled in the art willtherefore appreciate that such a platform can be readily programmed toserve as the above-described controller 51, either as a dedicatedcapability or, more likely, as a shared resource.

Referring now to FIG. 6, an illustrative example will be provided. Inthis example, a mobile node (M2) transmits a registration request 60 toa Packet Data Serving Node (this request comprising particularly, inthis example, an MIP_REG_REQ wherein the “B” bit of this request hasbeen set). This request serves, at least in part, to indicate a desireto receive future broadcast packets as may be issued by the Home Agent(HA).

Recognizing the nature of this request, the Packet Data Serving Nodethen transmits a registration request 61 on behalf of the mobile node tothe Home Agent. This registration request 61, however, also includes anindication that the Packet Data Serving Node can support a sharedversion broadcast packet handling approach. (More particularly, in thisexample, the registration request 61 comprises an MIP_REG_REQ where the“B” bit has been set and further comprises a corresponding broadcastNVSE that specifies this capability of the Packet Data Serving Node.)

In this illustrative example, the Home Agent is itself capable of alsosupporting the shared version broadcast packet handling approach andtherefore returns to the Packet Data Serving Node a reply message 62that, in addition to confirming that future broadcast packets will besent to the mobile node, also confirms that the Home Agent can and willsupport such broadcast packets through use of the indicated handlingapproach. (In this illustrative example, this reply message 62 comprisesan MIP_REG_REPLY having a set “B” bit and further comprising a broadcastNVSE portion that signals to the Packet Data Serving Node the aboveindicated confirmation and status.)

The Packet Data Serving Node then processes this reply message 62 todetermine 63 whether the Home Agent will support the shared versionbroadcast packet handling approach. More particularly, in thisillustrative example, the Packet Data Serving Node ascertains whetherthe reply message 62 includes the above-described broadcast NVSE thatindicates this status for the Home Agent. In this illustrative example,where the Home Agent has the requisite capability and has provided thecorresponding indication to the Packet Data Serving Node, thisdetermination yields a true result and the Packet Data Serving Node thendetermines 65, in this example, whether there is an existing relevantcontext for this Home Agent. (In the event where the Home Agent eitherdoes not have the requisite capability and/or is otherwise unwilling tosupport the shared version broadcast packet handling approach, thePacket Data Serving Node can delete 64 any previously stored orestablished broadcast Home Agent context.)

When no broadcast context presently exists for the Home Agent, thePacket Data Serving Node can add 66 such a context for this Home Agentto its available stored resources. In any event, the Packet Data ServingNode can then add 67 information regarding the mobile node to a list ofbroadcast listeners for this particular Home Agent.

The Packet Data Serving Node then transmits a reply message 68 to themobile node (in this illustrative example, this reply message 68comprises an MIP_REG_REPLY message wherein the “B” bit is set).

Continuing with this illustrative example, at some future point the HomeAgent has a broadcast packet to be distributed. In this case, where theHome Agent and Packet Data Serving Node have negotiated use of theshared version broadcast packet handling method, the Home Agent canprovide this broadcast packet 69 (or packets) to the Packet Data ServingNode in the company of, for example, an indication that the Packet DataServing Node itself comprises the destination. Upon receiving thisbroadcast packet and determining a need to effect further distributionusing the shared version broadcast packet handling method, the PacketData Serving Node can then replicate 70 the broadcast packet(s) andforward them on to each mobile node as appears in the list as beingassociated with this Home Agent via its context.

The Packet Data Serving Node can then use this recovered informationregarding the mobile node(s) to facilitate transmission of thesereplicated broadcast packets. For example, as illustrated, the PacketData Serving Node can transmit a first one of the replicated broadcastpackets 71 to the first mobile node mentioned earlier in this exampleand a second replicated broadcast packet 72 to another mobile node (M1)as has also effected this same kind of registration process.

So configured, those skilled in the art will appreciate that aconsiderable reduction in Home Agent to Packet Data Serving Node trafficcan be expected when these network elements are able to support, andchoose to support, such a process, as only a single broadcast packetneed to provided by the Home Agent to the Packet Data Serving Node tofacilitate provision of that content to a considerably larger number ofmobile nodes. At the same time, however, these teachings remaincompatible with non-capable elements as existing broadcast packethandling approaches also continue to be supported. The dynamiccapabilities described herein provide the opportunity to effectpotentially considerable bandwidth savings while also permitting aphased or even partial rollout of such a capability over the elements ofa given network.

Those skilled in the art will recognize that a wide variety ofmodifications, alterations, and combinations can be made with respect tothe above described embodiments without departing from the spirit andscope of the invention, and that such modifications, alterations, andcombinations are to be viewed as being within the ambit of the inventiveconcept. For example, in some settings, it may be desirable to provide athird broadcast packet handling approach that differs from either of thefirst and second approaches, and which third approach serves toaccommodate some specific condition of concern.

1. A method for operating a Home Agent, the method comprising: at theHome Agent, receiving an indication from a first network element that agiven mobile node using mobile Internet Protocol should receivesubsequent broadcast packets as sourced by the Home Agent; at the HomeAgent, automatically determining whether to support such subsequentbroadcast packets using a first broadcast packet handling approach or asecond broadcast packet handling approach; and at the Home Agent,determining whether to update a list to reflect whether the firstnetwork element supports the second broadcast packet handling approach,wherein the list is stored at the Home Agent and identifies networkelements that support the second broadcast packet handling approach. 2.The method of claim 1 wherein said receiving the indication from thefirst network element that the given mobile node using mobile InternetProtocol should receive subsequent broadcast packets includes: receivinga registration request that indicates that subsequent broadcast packetsare to be sent to the given mobile node.
 3. The method of claim 2wherein said automatically determining whether to support suchsubsequent broadcast packets using the first broadcast packet handlingapproach or the second broadcast packet handling approach includes:determining whether the registration request has an indication that thefirst network element supports the second broadcast packet handlingapproach.
 4. The method of claim 3 wherein said determining whether theregistration request has the indication that the first network elementsupports the second broadcast packet handling approach includes:determining whether the registration request has at least one normalvendor specific extension (NVSE) having an indication that the firstnetwork element supports the second broadcast packet handling approach.5. The method of claim 3, further comprising, if the registrationrequest has the indication that the first network element supports thesecond broadcast packet handling approach, providing an indication tothe first network element that the Home Agent is also able to supportthe second broadcast packet handling approach.
 6. The method of claim 3,further comprising, if the registration request has the indication thatthe first network element supports the second broadcast packet handlingapproach, including the first network element in the list.
 7. The methodof claim 6, further comprising: associating, in the list, the givenmobile node with the first network element if the first network elementis determined to support the second broadcast packet handling approach.8. An apparatus, comprising: a Home Agent that includes: an interface toa network element; a memory; a list, stored in the memory of the HomeAgent, that represents whether to use a first broadcast packet handlingapproach or a second broadcast packet handling approach if forwardingbroadcast packets to a mobile node via the network element, wherein thelist includes a list of network elements that support the secondbroadcast packet handling approach; and a controller operably coupled tothe interface to the network element and the list and configured toupdate the list.
 9. The apparatus of claim 8 wherein the list furtheridentifies mobile nodes that are associated with each of the networkelements in the list.
 10. The apparatus of claim 8 wherein thecontroller is configured to receive a signal from the network elementthat indicates that the network element supports the second broadcastpacket handling approach.
 11. The apparatus of claim 10 wherein thecontroller is further configured to transmit a signal to the networkelement that indicates that the Home Agent supports the second broadcastpacket handling approach.
 12. An apparatus, comprising: means forreceiving, at a Home Agent, an indication from a first network elementthat a given mobile node using mobile Internet Protocol should receivesubsequent broadcast packets as sourced by the Home Agent; andcontroller means, at the Home Agent, for determining whether to supportsuch subsequent broadcast packets using a first broadcast packethandling approach or a second broadcast packet handling approach, andfor determining whether to update a list to reflect whether the firstnetwork element supports the second broadcast packet handling approach,wherein the list is stored at the Home Agent and identifies networkelements that support the second broadcast packet handling approach. 13.The apparatus of claim 12 wherein the list further identifies mobilenodes that are associated with each of the network elements in the list.14. The apparatus of claim 12 wherein the means for receiving isconfigured to receive a signal from the first network element thatindicates that the first network element supports the second broadcastpacket handling approach.
 15. The apparatus of claim 12 wherein thecontroller means controls transmission of a signal to the first networkelement that indicates that the Home Agent supports the second broadcastpacket handling approach.
 16. An apparatus, comprising: an interface toa mobile Internet Protocol-compatible wireless mobile node; an interfaceto a Home Agent; a memory; a list, stored in the memory, that representswhether to use a first broadcast packet handling approach or a secondbroadcast packet handling approach different from the first broadcastpacket handling approach if forwarding broadcast packets from the HomeAgent to the mobile node, wherein the list includes a list of HomeAgents that support the second broadcast packet handling approach; and acontroller operably coupled to the interface to the mobile node, theinterface to the Home Agent, and the list, wherein the controller isconfigured to update the list to add the Home Agent if the Home Agent isdetermined to be capable to support the second broadcast packet handlingapproach, and wherein the controller is further configured to remove theHome Agent from the list if the Home Agent is determined to be capableto support the first broadcast packet handling approach and isdetermined to not be capable to support the second broadcast packethandling approach and if the Home Agent is presently identified in thelist.
 17. The apparatus of claim 16 wherein the list further identifiesmobile nodes that are associated with each of the Home Agents in thelist.
 18. The apparatus of claim 16 wherein the apparatus comprises aPacket Data Serving Node.
 19. The apparatus of claim 16 wherein thecontroller is further configured to signal to the Home Agent that theapparatus supports the second broadcast packet handling approach. 20.The apparatus of claim 19 wherein the controller is further configuredto receive a signal from the Home Agent that indicates that the HomeAgent supports the second broadcast packet handling approach.